Pointer type speedometer



Jal'l- 14, 1936- R. o, HELGEBY POINTER TYPE SPEEDOMETER Filed Sept.

v i ZL. mr vwl 9 Z Jan- 14, 1936, R. o. HELGEBY POINTER TYPE SPEEDOMETER Filed Sept. 17, 1928 3 Sheets-Sheet 2 Jam. 14, 1936. R. o. HELGEBY 2,02?,589

POINTER TYPE SPEEDOMETER Filed sept. 17, 1928 3 sheets-sheet 3 Hmm Patented Jan. 14, 1936 UNITED STATES PATENT OFFICE POINTER TYPE SPEEDOMETER Ware Application September 17, 1928, Serial No. 306.369

2 Claims.

This invention relates Ito measuring instruments and has been designed as an improvement in a combined speedometer and odometer for use particularly on vehicles to measure speed and the distance travelled.

An object of the invention is to provide a simple form of speedometer of the pointer type, and one economical to manufacture and easy to assemble. Other objects and advantages will be apparent from the following description.

In the drawing:

Figure l is a iront elevation with parts broken away;

Figure 2 is a transverse section on line 2--2 of Figure l;

Figure 3 is a transverse section on line 3 3 of Figure l;

Figure l is a transverse section on line 4 4 of Figure 3;

Figure 5 is a view in front elevation of the odometer supporting frame;

Figure 6 is a View in front elevation of the main frame having the rotor in place;

Figure 7 is a section on line '5 1 of Figure 3; 25y i gure 8 is a central sectional view of a modiorm of pointer type speedometer, this p doineter using a mounting plate;

gure 9 is a central sectional view showing parts in elevation, the view being of the side opgdposite to that shown by Figure 8;

Figure l0 is a vertical front elevation of the mounting plate; and

Figure 11 is a vertical side elevation of the same.

Referring to the drawing, there is illustrated a complete speedometer unit in which a pointer type of speedometer is combined with an odometer employing internal gear transfer mechaand a double reduction ratchet drive.

In the drawing, numeral 6 represents a main supporting frame. It is intended that this frame shall be made by the process of die casting. As is customary, this frame is to be placed within a casing I2. Studs Ill are used to secure the frame 45 in the casing. These studs extend from the frame and through the casing, suitable nuts I4' being threaded on the studs to clamp the casing and frame together.

The frame is formed with a shank I0 in 50 which is a suitable bore for a rotor shaft I6. The bore serves as a shaft bearing. A disc-like retainer i8 is passed through an opening in shank I6' and enters a groove in shaft I6. When the casing is assembled upon the frame 55 its iiange I2 serves, as clearly shown in Figure 2, to hold the retainer I 8 in position. A bushing 20, its end formed as an eccentric 22, is pressed upon rotor shaft I6. To the end of rotor shaft I6 is xed a disc-shaped rotor 24 by riveting over the ends of the shaft as at 24.

The rotor shaft is driven by a speedometer cable, as usual. At II' is shown a fiexible drive cable, its tip II being of the key type and received in a radial slot of the rotor shaft. The exible cable I'I is enclosed in a housing II". Engaged with the flange on the end of the housing is a coupling I9, which is threaded to the shank I0' to hold the housing in assembled relation with the shank and the drive cable tip with the rotor shaft.

Numeral 56 represents an odometer frame, which frame is to be made as a stamping. It is cup-shaped and of non-magnetic material, such as brass. As shown in Figure 2, it is positioned above magnet 58 carried by the main frame. It is fastened to 'the main frame and held in assembly by the studs I4, already mentioned as the fastening means between the casing and the main frame. The cup-shaped frame 56 has a circular depression 60, which snugly fits a like-shaped bore 60 in the frame I0. It is on a ledge within said bore that the annular magnet 58 rests. This arrangement acts to eX- actly locate the frame 56. The peripheral wall 56 of frame 56 snugly ts` within casing I2. There is thus provided a quick and easy means of locating the odometer frame relative to the main frame and also of locating the combined instrument in the casing I2. The bottom of frame 56 may have lanced out ears 62, as shown in Figures 2 and 5. These lanced out ears engage the magnet and when the frame 56 is secured to frame I0, these ears rmly clamp the magnet in position.

Riveted to the under side of frame 56 is a temperature compensator 64, as shown in Figure 3. This compensator is intended to be received between the poles of the magnet and its function is to make corrections for errors in the reading of the needle due to changes in temperature. The magnet is accurately located in position in the act of assembling the frame member 56 since in so locating the frame 56, the compensator 64 is received between the poles of the magnet.

Frame 56 is further formed with an angularly turned arm 66 which projects o-ver the center of the frame to serve as a supporting means for the spindle of the indicating pointer. This arm 66 is provided with screw threads, as at 68, to

receive a jewel screw 10. Around the screw 10 is rotatably mounted a hair spring regulator 12. Ears I4 on regulator 12 are bent over arm 66, as shown in Figure 2, to retain the regulator 12 in position. In its rotating movement, the regulator is guided by member 10.

A spindle 'I6 carries a collar 13. The hair spring is connected at one end of this collar. Its other end is secured to an end of arm '|2 in the usual manner. Pressed on spindle 16 are collars 18, between which is positioned disc 80 which is securely held to the spindle. The spindle 16 is centered in the axis of drive shaft |6 by means of a rotating cup 82 positioned in a bore at the upper end of shaft I6, and by means of the stationary jewel lll. Pressed on the end of spindle I6 is an indicating pointer bushing 84 to which the pointer 86 is secured as by riveting. Y

By the provisions described, there is provided a combined speedometer and odometer employing a very simple odometer supporting frame, this frame being formed as a stamping and all of its openings being punched, not drilled, as is the case when such a frame is made by casting. Reduced cost is thereby effected. The

Vmaking of arm. 66, serving as a jewel frame,

an integral part of the odometer frame contributes to the simplicity and economy in manufacture.

'Ihe lining up and centering of the spindle by locating frame 56 directly in the die cast frame I0 through the provision of depression 60 snugly fitting opening 60 is of help in assembling the parts. Also, the use of studs I4 to hold the frames together and also to clamp the combined instruments in the casing contributes to the same result. The anchoring of the transfer pinion stamping in grooves 63 and 65 is a further simplification which cam be readily used, thus avoiding the usual transfer pinion shafts supported by the odometer frame.

The mechanism, as a whole, is accurately and quickly assembled in the casing by the provision of the peripheral portion 56. The casing flange l2 serving to hold the shaft retainer I8 in position represents another renement in construction.

By the use of a speedometer of the pointer type, steady performance and uniformity in action are secured since a light weight disc with little inertia is used. Such a disc is exposed to a strong magnetic iield of great uniformity owing to the use of the annular flat magnet.

' The straight-away drive entering horizontally .which this instrument employs affords a convenient means for the drive cable and for the coupling. This is also of importance in simplicity and low cost.

A pointer type speedometer also affords a means for matching a clock with a speedometer in the panel.

The construction is also designed to use parts which are also used lin the manufacture of a standard tachometer, these parts being the rotor, the magnet, the disc, the spindle, the pointer, the hair spring and the bearings. The drive shaft i6 is a slight modification of the corresponding shaft of the tachometer, being some- 5 what longer to accommodate the bushing carrying the eccentric pin 22. The main supporting frame must also be somewhat changed to accommodate the ratchet drive for the odometer.

Figures 8 to 11 illustrate a somewhat modied 10 form of the invention. This form also makes use of a pointer type of speedometer. This form is provided with a mounting plate 96 similar to that used in well-known speedometers for mounting the frame of the speedometer in the 15 casing. It has ears H0, |H and H2. Between these ears are journaled the figure Wheels H3. Backwardly projecting lugs H4 and H5 are provided to act as spacers and to mount this mounting plate on the die cast frame H6. These lugs 20 H4 and H5 are bolted to ears H1 on the frame H6, as shown in Figure 11. The same fastening means also serves to clamp magnet |28 in place, as illustrated in Figure 1l.

The frame |16 supports the driving mecha- 25 nism composed of driven shaft H8 journaled in the shank H6 of frame H6 and to this shaft is xed rotor |26. Numeral l2! represents a disc carrying the spindle |22 and pointer |23. Pointer |23 rotates over a conventional dial |24. 30 Spindle |22 is centered at |25 and |26 in suitable bearings in the end of an arm |21 stamped 'from plate 653 and in the end of the rotor shaft. The magnet 26 is positioned on the frame substantially as in the previous form. The double 35 reduction gearing consists of an eccentric |29 on bushing |30 carried by rotor shaft H8. On this bushing is journaled a pawl |3l, which latter is urged into engagement with ratchet wheels |32 by a spring clip |32'. Gear |33 driven in 40 this way meshes with an intermediate gear |34, itself driving the trip and season Wheels H3 in a manner which will be obvious from the description of the form rst described.

This form of the invention differs from the form first described by the use of a mounting plate 99. The mechanism is thereby simplified, particularly the die cast frame.

I claim:

l. In a measuring instrument, a main frame, a magnet supported by said frame, a supplementary frame, a thermostatic compensator adapted to be received between the poles of said magnet and secured to said second frame, means to secure said second frame to said rst frame in a 56 predetermined position whereby said compensator locates said magnet in a predetermined position on said main frame.

2. The invention dened by claim 1, said second frame having resilient tongue means to 50 engage and hold said magnet on said first frame when the two frames are secured together.

RALPH O. HELGEBY. 

